1. Field of the Invention
The invention relates to communications systems and in particular to such systems employing optical transmission links.
2. Discussion of the Prior Art
Modern computing and communications systems require ever higher data transmission rates. The speed of transmission is limited by the usable bandwidth of the transmission medium. In the case of transmission along coaxial cables, for example, data rates are limited to around a few hundred megahertz over large distances.
Optical transmission systems offer theoretical bandwidths of peta-hertz. If the transmission is in a dispersive medium, then this data rate is considerably reduced. In commercially available single mode optical fibres, for instance, the theoretical limit is greater than a few hundred gigahertz. This limitation arises from the maximum speeds at which the driving electronics can operate.